1. Field of the Invention
This invention relates to apparatus used to heat liquids and, more particularly, to such apparatus designed to generate heat by friction.
2. Description of the Related Art
Various steam generators or liquid heating apparatus have been developed which use friction to generate heat. For example, Schaefer, (U.S. Pat. No. 3,791,349), discloses an elaborate apparatus and method for producing pressurized steam by creating shock waves in a distended body of water. The rotor in this apparatus presents a complex and tortuous passageway to create the amount of water hammer necessary to effect a significant rise in the temperature of the water. In Griggs, (U.S. Pat. No. 5,188,090), an apparatus for heating liquids is disclosed having a cylindrical rotor which features surface irregularities. The rotor is rotated in a housing filled with a liquid to be heated. Shock waves are also produced in this apparatus to heat the liquid.
While the apparatus found in the prior art have been shown to be reasonably efficient in generating heat and/or pressure in water and other liquids compared to more traditional methods (i.e., burning fossil fuels or using electrical resistance coils), all of the apparatus found in the prior art are relatively complex structures which use internal support bearings and shaft seals which require periodic maintenance and replacement. More importantly, none of the apparatus found in the prior art are capable of using water hammer to generate usable mechanical energy as well as thermal energy. An apparatus which generates heat in liquids, which has no support bearings, shaft seals or any other mechanical friction points, which will never wear out or require maintenance of any kind, which is simple to understand and operate, which is simple and less expensive to manufacture, and which operates more efficiently due to its ability to generate useable mechanical energy is clearly and greatly needed.